Sheet-metal knob



(No Model.)

' A. T. MATTHEWS.

SHEET METAL KNOB.

Patented May 31, 1892? UNITED STATES PATENT FFICE.

AMBROSE T. MATTHEWS, OF WVORCESTER, MASSACHUSETTS.

SHEET-METAL KNOB.

SPECIFICATION forming part of Letters Patent No. 475,880, dated May 31,1892.

Application filed December 23, 1891. Serial No. 415, 7 N m To 00% whomit may concern:

Be it known that I, AMBROSE T. MAT- THEWS, a citizen of the UnitedStates, residing at lVorcester, in the county of Worcester and State ofMassachusetts, have invented a new and useful Improvementin SheetMctalKnobs, of which the following is a specification.

The aim of this invention is to produce a new and improved sheet-metalknob; and to this end the invention consists of the device described andclaimed in this specification, and illustrated in the accompanyingdrawings, in which Figure 1 is an elevation of my improved knob. Fig. 2is a central sectional view of the same. Fig. 3 is a plan of thebase-section. Fig. 4 is a view of one form of disk used in thebase-section. Fig. 5 is a similar view of a modified form of disk; andFig. 6 is a view, on a slightly-reduced scale relatively to the otherfigures, of astrip of metal, showing the way in which the blanks for thebase-sections may be cut out.

My invention relates, primarily, to the basesections of the ordinarysheet-metal knobs and to a new and improved way of making the same.- Thebase-sections of sheet-metal knobs have been made before with two leavesand with four leaves. The four-leaved blank has the advantage that thedie will not slip on the blank in shaping or striking the same up, aswhen the die commences to act on the blank the same willbeguided fromfour points, and hence cannot slip away from the center of the blank;but the four-leaved blank cannot be economically cut from the metal. Thetwo-leaved blank can be economically cut from the metal; but the same isvery apt to slip in the dies and break laterally at the corner where themost strain comes.

My invention, therefore, aims to produce a blank for the base-sectionswhich will combine the advantages of both the two-leaved and thefour-leaved blank. To this end I form the blank with a number of wholeleaves, preferably two, and a partial leaf or projection between eachwhole leaf. I may also, if desired, place a disk or ring in the top ofthe base-section, so that when the cap or cover is closed over the samethe edge of tion will resist pressure.

Referring now to the drawings and in detail, A represents thebasesection of a knob embodying my invention, and B the cap or cover ofthe same. The base-section A may be pricked in or tapped in the bottomin the usual manner to receive the ordinary screw a, having washer b.The base-section is struck up from a blank, as O. This blank has the twoleaves E and F, which are made convex at their ends, as shown, to formthe top edge of the section, and between these leaves E and F are formedthe projections or partial leaves G and H. WVhen the base-section isstruck up, a sort of half-moon-shaped hole will be left in the sectionbetween each of the leaves, the bottom of the holes being formed by theedge of the partial leaves, which preferably are curved, as shown, and,further, the partial leaves or projections will act to keep the blank inthe center of the dies during this operation. This will give abase-section of very handsome contour or shape. The blanks for thebase-sections may be economically cut out, as shown in Fig. 6, bylapping the sides of the leaves of one row of blanks into or between theleaves and the partial leaves of the next row, and this will of coursecheapen the manufacture. I preferably do not bring the edges or sides ofthe leaves together at the top to form a continuous edge; butI form thesections in the dies with a sort of rim or annular portion (Z at the topof the same, and into this rim I drop a disk or ring. This disk may besolid, as R, in the form of a washer, as V, or a wire ring. WVhen thecap is closed over the base-section containing the disk or ring, theedge of the section will resist the pressure and will prevent the capfrom springing the leaves of the base-section. I find that this is asuperior construction over the base-section with the leaves buttedtogether to form a continuous edge, as the latter is difficult to make,requiring exact dies, and also when the cap is applied to the latterwith any more than the usual pressure the leaves are apt to snap pastone another and thus of course defeat the very object of the continuousedge.

I am aware that it is not new to place a disk the base-secbetween thebase-section and the cap for the purpose of reinforcing the fasteningdevice; but so far as I am informed it is broadly new to place a diskinside of and within the basesection and to close the edge of the capover the edge of the base-section, whereby the basesection will bestrengthened or reinforced to resist the pressure due to the closingover of the cap.

An economical construction with my device is to use a washer on thelarger size knobs and the center cut out of the washer as the disk forthe smaller sections.

So far as the broad idea of my invention is concerned the blank may haveany desired number of whole leaves with partial leaves formed betweenthe same.

WVith my improved construction, as before described, I am able to make'knobs of very thin stock, and I contemplate using the disk or ring inall forms of base-sections to which a cap is to be applied, no matterwhether the section is leaved or solid.

Modifications of the construction herein shown may be made by a skilledmechanic Without departing from the scope of my invention.

Having thus fully described my invention, what I claim, and desire tosecure by Letters Patent, is-

l. A sheet-metal knob consisting of a basesection and a cap, saidbase-section formed from a blank having leaves and partial leaves orprojections formed between the whole leaves, substantially as described.

2. A sheet-metal knob consisting of a basesection and a cap, saidbase-section formed from a blank having two leaves convex on their endsand projections or partial leaves formed between each of said wholeleaves, substantially'as described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

AMBROSE T. MATTHEWS.

\Vitnesses:

JAMES J. RAFFERTY, LoUIs W. SOUTHGATE.

